CN1314004C - Information recording medium substrate, information recording medium and manufacturing method for the medium - Google Patents

Abstract

A substrate for an information recording medium, which is made of a glass or crystallized glass, (1) which has a region that has a spectral light transmittance of 50% or less converted in terms of a thickness of 2 mm in a wavelength range of 2,750 nm to 3,700 nm, (2) which shows a spectral light transmittance of 70% or less converted in terms of a thickness of 2 mm over whole wavelength range of 2,750 nm to 3,700 nm, (3) which contains an infrared absorbent that is a specific metal oxide and is for use in a perpendicular magnetic recording medium, (4) which is to be heated by irradiation with infrared ray and contains more than 200 ppm of water, or (5) which contains an infrared absorbent that is a specific metal oxide and is used as a substrate to support a multi-layered film including an information recording layer to be formed by sputtering after heating by irradiation with infrared ray, an information recording medium comprising a multi-layered film including an information recording layer formed on any one of the above substrates, and a process for producing an information recording medium.

Description

Information recording medium substrate, the manufacture method of information recording carrier and this medium

Technical field

The present invention relates to a kind of information recording medium substrate, the method of a kind of information recording carrier and a kind of manufacturing information recording medium, more especially, the present invention relates to be used for a kind of information recording medium substrate with high IR beta radiation efficiency of heating surface, a kind of information recording carrier that contains multilayer film, this film has and is formed on on-chip one deck information recording carrier layer, and a kind of method of making good information recording carrier, this method comprises substrate is remained on the state of temperature that is suitable for forming multilayer film.

Background technology

Usually as for example substrate of the information recording carrier of disk, use has the substrate (for example JP-A-2001-180969) that lithium alumina silicate glass is made that contains of high Young's modulus, the perhaps substrate made of glass ceramics, this glass ceramics have the crystallizing layer (for example JP-A-2000-119042) that the glass heat treatment precipitation by specific composition gets.

Information recording carrier is to prepare by form a kind of multilayer film on above-mentioned substrate, and these multilayer film comprise an information recording layer.For example, when multilayer film are formed on the above-mentioned substrate, this substrate at first is introduced into the substrate heating zone of film forming device and is heated to can film forming temperature by sputter, after the temperature of substrate fully raises, this substrate is sent to the first film and forms the district, and one deck is equivalent to the undermost layer of multilayer film and forms on substrate.Then, this substrate is sent to second film and forms the district, and forms a layer on orlop.This substrate is formed rearward end zone, district and is transmitted to form aforesaid each floor along film, on substrate, form the multilayer film that contain information recording layer thus, because it is to carry out under by the low pressure that reaches of bleeding with vacuum pump that above-mentioned heating and film form, above-mentioned heating must be undertaken by non-contact method, therefore is suitable for heated substrate by radiation heating.

Need before reaching than the lower temperature of the temperature that is suitable for film formation, substrate temperature carry out the formation of above-mentioned film, consuming time when oversize when forming this layer, the temperature of substrate reduces, and cause a problem, promptly form the substrate temperature that the district is difficult to obtain being enough to form a kind of floor at the film that is in than after-stage., can consider substrate is heated to higher temperature for but substrate is remained on the film formation temperature for a long time.When substrate firing rate hour, need to increase heat time heating time, and need to increase the residence time of substrate in the heating zone.Substrate forms the residence time of distinguishing at each film will be longer, and the film in stage forms the enough substrate temperatures of district's maintenance no longer afterwards, in addition, and the output of also having no idea to improve.

To add temperature in order increasing, perhaps can to use the method for high-intensity rayed substrate, yet problem is that the substrate light absorption of making of the substrate made of glass or glass ceramics is low, causes to be difficult to obtain the enough thermal efficiency.

Summary of the invention

In these cases, an object of the present invention is to provide a kind of information recording medium substrate, the infrared radiation efficiency of heating surface height of this information recording medium substrate, a kind of information recording carrier that contains multilayer film, this film contains and is formed on on-chip one deck information recording carrier layer, and a kind of method of manufacturing information recording medium, wherein be suitable for forming the state of temperature of multilayer film or substrate fully heated make good information recording carrier at short notice by above-mentioned substrate is remained on.

For achieving the above object, the inventor has carried out the research of making great efforts, found that the substrate that makes with glass or glass ceramics (1) has that spectral-transmission favtor is predetermined value or littler zone in particular range of wavelengths, (2) substrate made from glass or glass ceramics is a predetermined value or littler in the spectral-transmission favtor of whole particular range of wavelengths, (3) substrate made from glass or glass ceramics contains the infrared absorbent that the special metal oxide constitutes, and (4) have the glass of predetermined moisture content or substrate that glass ceramics is made is suitable for above-mentioned purpose as information recording medium substrate.And find to make good information recording carrier and can be undertaken, perhaps by being that predetermined value or the bigger multilayer film that contain information recording layer that form on substrate down carry out in average firing rate in the heating zone by utilizing infrared irridiation to heat any in these substrates and form the multilayer film that contain information recording layer.The present invention finishes on the basis of above-mentioned discovery.

That is,, provide according to the present invention;

(1) a kind of information recording medium substrate, it is made by glass or glass ceramics, and its spectral-transmission favtor is 50% or littler, with 2,750nm-3, thickness is the 2mm expression (after this being called as " substrate 1 ") that converts in the 700nm wavelength coverage.

(2) a kind of information recording medium substrate, it is made by glass or glass ceramics, and its spectral-transmission favtor is 70% or littler, with whole 2,750nm-3, thickness is the 2mm expression (after this being called as " substrate 2 ") that converts in the 700nm wavelength coverage.

(3) a kind of information recording medium substrate, it is made by glass that contains infrared absorbent or glass ceramics, this absorbing agent is the oxide of the metal of at least a chosen from Fe, copper, cobalt, ytterbium, manganese, neodymium, praseodymium, niobium, cerium, vanadium, chromium, nickel, molybdenum, holmium or erbium, and it is used for perpendicular magnetic recording medium (after this being called as " substrate 3 ").

(4) a kind of as top (1), (2) or (3) described information recording medium substrate, it will utilize the infrared irridiation heating.

(5) a kind of information recording medium substrate, it is made by glass or glass ceramics, and is moisture greater than 200ppm, and will be utilized infrared irridiation heating (after this being called as " substrate 4 ").

(6) a kind of information recording medium substrate, it is made by glass that contains infrared absorbent or glass ceramics, this absorbing agent is the oxide of the metal of at least a chosen from Fe, copper, cobalt, ytterbium, manganese, neodymium, praseodymium, niobium, cerium, vanadium, chromium, nickel, molybdenum, holmium or erbium, and it is as the substrate of carrying multilayer film, this film will form by sputter after the infrared irridiation heating, and these multilayer film contain information recording layer (after this being called as " substrate 5 ").

(7) as each described a kind of information recording carrier that contains the multilayer film that form on information recording medium substrate in top (1)-(6), these multilayer film contain information recording layer.

(8) a kind of by on information recording medium substrate, forming the method that the multilayer film contain information recording layer come the manufacturing information recording medium, this method comprises that forming the district along continuous film transmits the described substrate that is at least 10 ℃ of/second heating in the heating zone with average firing rate, and is formed for constituting the floor of described multilayer film continuously so that form multilayer film (after this being called as " method 1 ") in film formation district.

(9) a kind of as top (8) described information recording medium manufacturing method wherein transmits information recording medium substrate so that have a residence time in the heating zone, and has a residence time in each film formation district, and its residence time is mutually the same.

(10) a kind of as top (8) or (9) described information recording medium manufacturing method, wherein this information recording medium substrate is entered and leaves heating zone and each film formation district by synchronous driving.

(11) a kind of as top (8), (9) or (10) described information recording medium manufacturing method, wherein said information recording medium substrate utilize the infrared irridiation heating.

(12) a kind of information recording medium manufacturing method, it comprise utilize infrared irridiation heating as each described information recording medium substrate in top (1)-(6) and as described on the substrate formation contain the multilayer film (after this being called as " method 2 ") of information recording layer.

(13) a kind of information recording medium manufacturing method, it is included in as forming information recording layer on each described information recording medium substrate in top (1)-(5) and utilize infrared radiation to heat this substrate (after this being called as " method 3 "), and

(14) a kind of information recording medium manufacturing method, it is included in and forms information recording layer on the information recording medium substrate, this substrate is made by glass that contains infrared absorbent or glass ceramics, this absorbing agent is the oxide of at least a metal of chosen from Fe, copper, cobalt, ytterbium, manganese, neodymium, praseodymium, niobium, cerium, vanadium, chromium, nickel, molybdenum, holmium or erbium, and utilizes infrared irridiation to heat this substrate (after this being called as " method 4 ").

Embodiment

The preferred embodiments of the invention will be according to the order explanation of information recording medium substrate, information recording carrier and information recording medium manufacturing method.

＜information recording medium substrate 〉

Finish by information recording medium substrate provided by the invention according to following discovery.

A kind of SiO that contains that is especially suitable for use as information recording medium substrate ₂And Al ₂O ₃Glass or contain SiO ₂And B ₂O ₃Glass 2,750nm-3 has absorption peak in the wavelength coverage of 700nm, its glass ceramics also has above-mentioned feature.

Substrate for the substrate that utilizes infrared irridiation effectively to heat to make with this glass or this glass ceramics are made it is desirable to use have peaked infrared ray in above-mentioned wavelength coverage.

When by the infrared irridiation heated substrate, some layers reflecting part infrared ray in substrate formation, and the infra-red intensity that absorbs reduces, therefore it is desirable to heated substrate before these layers formation begins, when after forming information recording layer, using the infrared irridiation heated substrate, can utilize the big substrate of infrared ray absorbing effect to obtain the enough big thermal effect that adds.

For increasing firing rate, can expect making the infrared ray spectral intensity is that peaked wavelength and substrate absorption spike length match each other, and increases infra-red intensity.Under the situation of condition of high temperature carbon heater as a kind of infrared source, the input that can increase carbon heater increases infra-red intensity.But, be blackbody radiation if be taken as from the radiation of carbon heater, because increasing, input cause Heating Zone Temperature to increase, infrared ray spectrum wavelength maximal value is to short wavelength side shifting with depart from above-mentioned glass absorbing wavelength scope as a result.Therefore the consumed power that needs excessively to increase well heater increases heating of substrate speed, and the problem that causes that well heater reduces serviceable life is arranged.

From top viewpoint, it is desirable to, the absorption of increase glass in above-mentioned wavelength coverage is carried out infrared radiation under the approaching each other situation of the absorption peak wavelength that makes ultrared spectrum maximal value wavelength and substrate, and the well heater input does not increase excessively.

Because substrate has chip shape, plate-like for example, following information recording medium substrate is desirable for increasing the efficiency of heating surface.

According to top achievement in research, had been found that before the multilayer film that contain information recording layer form (any before information recording layer forms, form and can add the layer of thermosetting can be) or after information recording layer forms, can be comprised with subtegulum 1-5 by the information recording medium substrate that infrared radiation is effectively heated not within the above-mentioned multilayer film scope.

(substrate 1)

Substrate 1 is a kind of information recording medium substrate, and it is made by glass or glass ceramics, with 2, and 750nm-3, thickness is the 2mm expression that converts in the 700nm wavelength coverage, has spectral-transmission favtor and be 50% or littler zone.

Substrate 1 comprises that chemistry strengthens substrate and the not chemical substrate that strengthens, and when substrate is strengthened by chemistry, near surface one ion exchange layer is arranged, and except this part, this substrate is made of homogeneous glass.When substrate is not strengthened by chemistry, whole substrate is made of homogeneous glass or glass ceramics, the homogeneous part will have constant absorption coefficient and constant scattering coefficient, and therefore above-mentioned spectral-transmission favtor can convert according to the known conversion method about the different substrate of thickness, strengthen the ion exchange layer that forms even exist by chemistry, the absorption coefficient of whole substrate also can be thought constant.Be arranged to incident angle by the measuring light incident angle that will (be called as " the main back side ") on a surface and come the measure spectrum transmissivity perpendicular to first type surface, information recording layer will be formed on this surface.Spectral-transmission favtor comprises by reflection of the light on the substrate surface and scattering also having the light absorption of substrate the inside and the effect that scattering causes.The first type surface of information recording medium substrate need have high flatness and smoothness.

Substrate 1 has above-mentioned spectral transmission performance, so that can increase the efficient of utilizing the infrared radiation heating.In addition, when the multilayer film that contain information recording layer formed, substrate 1 can be with high firing rate heating.Further, the substrate that is formed with information recording layer on it can utilize infrared radiation fully to be heated.

(substrate 2)

Substrate 2 is a kind of information recording carriers, and it is made by glass or glass ceramics, with 2, and 750nm-3, thickness is the 2mm expression that converts in the 700nm wavelength coverage, its spectral-transmission favtor is 70% or littler.

The substrate 2 that has high absorption in above-mentioned wavelength coverage can produce the effect identical with substrate 1, and the homogenieity of substrate 2, spectral-transmission favtor measurement and conversion method are identical with substrate 1.Preferred substrate 2 also has the performance of substrate 1 and the performance of itself.Promptly the infrared spectrum from the infrared source radiation is wide spectrum and has and preferably have the wavelength coverage that big absorption takes place to a certain extent that this scope is in the wide region that comprises the maximum spectral wavelength of infrared ray district, so that absorb ray effectively.

Substrate 2 has above-mentioned spectral-transmission favtor performance, so that can improve the efficient of utilizing the infrared radiation heating, and this substrate can heat under the high firing rate that is used to form the multilayer film that contain information recording layer, in addition, the substrate that is formed with information recording layer on it can be utilized infrared radiation and fully heats.

When substrate 1 or substrate 2 are made by glass ceramics, above-mentioned spectral-transmission favtor depends on the size and the density of crystal grain in the glass ceramics, and when crystallite dimension was big, the crystal grain scattering accounted for most that spectral-transmission favtor descends, even and absorption is little, spectral-transmission favtor also can be littler than above-mentioned predetermined value.When substrate of the present invention was made by glass ceramics, crystallite dimension was preferably 100nm or littler.When crystallite dimension is in this scope, little by the infrared diffusion that crystal grain causes, and think that grain density does not influence spectral-transmission favtor.Therefore determine that the principal element of above-mentioned spectral-transmission favtor is the infrared ray absorbing of glass ceramics.When substrate 1 and substrate 2 were all made by glass ceramics separately, preferred crystallite dimension was in above-mentioned scope.More preferably crystallite dimension is in being no more than the scope of 50nm, and in the scope particularly preferably in 1-50nm.

(substrate 3)

Substrate 3 is a kind of information recording carriers, it is made by glass that contains infrared absorbent or glass ceramics, this absorbing agent is the oxide of at least a metal of chosen from Fe, copper, cobalt, ytterbium, manganese, neodymium, praseodymium, niobium, cerium, vanadium, chromium, nickel, molybdenum, holmium or erbium, and it is used for perpendicular magnetic recording medium.

When above-mentioned infrared absorbent is in glass or glass ceramics, it shows very strong optical absorption at infrared region, this substrate 3 is used for perpendicular magnetic recording medium, in the production of perpendicular magnetic recording medium, the multilayer film that contain magnetic recording layer are at high annealing, therefore this magnetic recording media thermal treatment under than the higher temperature of longitudinal magnetic recording formula medium, and therefore its substrate need be heated to high temperature.In addition, after inculating crystal layer and soft magnetosphere form, when utilizing the infrared radiation heated substrate, substrate need be heated to temperature desired at short notice on substrate.When the substrate that has formed magnetic recording layer on it heats with infrared radiation, substrate temperature is fully improved by making substrate fully absorb the infrared ray that arrives substrate.For this purpose, need to improve the efficient of infrared radiation heated substrate.According to substrate 3, be increased in the light absorption of infrared region by adding infrared absorbent, can carry out effectively so that be suitable for producing the heating of perpendicular magnetic recording medium.

During the perpendicular magnetic recording medium that has carried out above-mentioned heating was betwixt produced, needing substrate temperature was 200 ℃ or higher, so substrate is heated to 200 ℃ or higher temperature and less than the glass transformation temperature of the material that constitutes substrate.The temperature of heated substrate is preferably at least 250 ℃ and less than the glass transformation temperature of the material that constitutes substrate, more preferably at least 300 ℃ and less than the glass transformation temperature of the material that constitutes substrate, also more preferably at least 450 ℃ and less than the glass transformation temperature of the material that constitutes substrate.In the above range, preferred especially said temperature is in being no more than 550 ℃ scope.

When the ferriferous oxide of above-mentioned infrared absorbent is introduced separately into, press Fe ₂O ₃Meter, its weight content is preferably 500ppm-5%, and more preferably 2,000ppm-5%, also more preferably 2,000ppm-2%, also more preferably 4,000ppm-2%.By introducing ferriferous oxide, can be increased in wavelength is 1,000nm and near absorption, and when thickness was 2mm, wavelength was 1, the spectral-transmission favtor of 000nm is 90% or littler.

Preferred above-mentioned substrate 3 also has the performance of substrate 1, the performance of substrate 2, perhaps substrate 1 and 2 performance, and the performance of himself.

Above-mentioned substrate 1,2 and 3 is suitable for heating with infrared radiation.Be discussed later by utilizing infrared radiation to heat.

(substrate 4)

Substrate 4 is a kind of information recording medium substrates, and it is made by glass or glass ceramics, and water cut is greater than 200ppm, and will heat with infrared radiation.

Above-mentioned water comprises the OH base, and its content is pressed H ₂O represents.Water or OH base have strong absorption at 3 mu m wavebands, therefore moisture glass or glass ceramics system substrate greater than 200ppm will have strong absorption at 3 mu m wavebands, promptly at wavelength 2,750nm-3, in the 700nm or near, so that can increase with the efficiency of heating surface between infrared radiation period of heating and can improve heating of substrate speed, above-mentioned water cut is preferably 220ppm or bigger.

Preferred above-mentioned substrate 4 also has the performance of substrate 1, the performance of substrate 2, or the performance of substrate 1 and 2, and the performance of himself.In addition, substrate 4 also is suitable for the substrate as perpendicular magnetic recording medium.

(substrate 5)

Substrate 5 is a kind of information recording medium substrates, it is made by glass that contains infrared absorbent or glass ceramics, this absorbing agent is the oxide of at least a metal of chosen from Fe, copper, cobalt, ytterbium, manganese, neodymium, praseodymium, niobium, cerium, vanadium, chromium, nickel, molybdenum, holmium or erbium, and it is as the substrate of the multilayer film that will form by sputter after the infrared radiation heating, and these multilayer film contain information recording layer.

The above-mentioned multilayer film that form by sputter after the infrared radiation heating comprise that (1) is by heating information recording medium substrate in the heating zone, then this substrate is sent to a plurality of continuous films and forms the district, and form the district at film and form the multilayer film that each floor forms by sputter, (2) a kind of multilayer film, it is included among the multilayer film of top (1), this film is to form by transmitting this substrate and it being equal to each other in the residence time of heating zone with in the residence time in each film formation district, and (3) a kind of multilayer film, it is included among the multilayer film of top (1), and this film is to form by the substrate synchronous driving being entered and leaves above-mentioned heating zone and film formation district.During multilayer film in above-mentioned (1)-(3) in each formed, heated substrate and form each layer by sputter and carry out under vacuum or low pressure preferably utilized infrared radiation to carry out above-mentioned heating, and this makes and can effectively heat under vacuum or low pressure.Though substrate 5 not only is suitable as substrate fixing and relative sputter, and is suitable as the substrate of tandem sputter, more preferably use substrate 5 usefulness to fix and the substrate of relative sputter and substrate more preferably fixing and relative sputter as the monocrepid charging.

Glass or glass ceramics are preferably 2-20 second at the residence time and the substrate of heating zone separately in the residence time that each film forms the district.Be at least 10 ℃/second for the desirable average firing rate of substrate, better is to be at least 15 ℃/second, and also better is to be at least 20 ℃/second, and better again is to be at least 30 ℃/second.On average firing rate is meant the value that substrate temperature before the heating and the difference that heats the meron temperature were got divided by heat time heating time.For preventing that Fast Heating from causing substrate damage, preferably average firing rate is adjusted to 200 ℃/second or littler.

Above-mentioned infrared absorbent is a kind of adjuvant that strengthens the infrared ray absorbing effect, and as illustrated about substrate 3, the amount of infrared absorbent is as described in about substrate 3.

Preferred above-mentioned substrate 5 also has the performance of substrate 1, and the performance of substrate 2, or the performance of substrate 1 and 2, or the performance of substrate 4 combine with himself performance.In addition, substrate 5 also is suitable for as the perpendicular magnetic recording medium substrate.

When the multilayer film that contain information recording layer are formed on such substrate or before the formation of above-mentioned multilayer film, carry out arbitrary heating of substrate among the above-mentioned substrate 1-5 with infrared radiation at once.For utilizing infrared radiation heating, the radiation spectrum maximum wavelength is 2,750nm-3, and the infrared source in the wavelength coverage of 700nm is suitable.Suitable this infrared source is a kind of well heater.When this well heater can be considered to black matrix, preferably heter temperature is adjusted to 600K-1,000K, 700K-900K more preferably is used to make near the coupling absorption peak of the maximum wavelength of radiation spectrum and substrate.

Suitable well heater is a carbon heater, because well heater is disposed in heating chamber, the partial pressure of oxygen in the heating atmosphere reduces, and wears out through peroxidation so can reduce carbon heater.

The center line average roughness Ra of substrate first type surface is preferably 005-1nm, so that have the desired smoothness of information recording medium substrate and reduce upward infrared diffusion of surface.

The flatness of substrate and the depth of parallelism requirement satisfied of information recording carrier with the need and deciding.

Each substrate is the disc-shape with center pit, and external diameter is about 10-95mm and has homogeneous thickness, and thickness is preferably in the scope of 0.1-2mm.

When substrate was heated, infrared radiation was used on the surface (first type surface) of in the preferred above-mentioned substrate formation being contained the multilayer film of information recording layer.

Infrared ray is reflected on above-mentioned multilayer film to a certain extent.Therefore it is desirable to before multilayer film form or need not heat the layer that can form form after (after for example inculating crystal layer in the perpendicular magnetic recording medium and soft magnetosphere form) carry out the infrared radiation heating.But, when the substrate that has formed information recording layer on it heats with infrared radiation, even add thermal effect fully owing on the information recording layer surface, reflecting the infra-red intensity reduction that arrives substrate, also can accessing, because the ultrared ability of this substrate absorption has improved.

Because the infrared ray absorbing effect of each above-mentioned substrate is big, compare with the substrate that other any infrared ray absorbing effect is little, the temperature decline rate that is caused by infrared radiation is little, therefore above-mentioned substrate keeps the long time being suitable for film forming substrate temperature, and constituting the glass of above-mentioned substrate or constituting the cooling velocity of substrate glass of glass ceramics of above-mentioned substrate little also is useful for following characteristics.In above-mentioned substrate, by moulding, perhaps so the glass of moulding is by machine work in the condition of high temperature for plastically deformable glass, and to form desirable shape, above-mentioned glass is low in condition of high temperature cooling velocity, makes so can spend long-time moulding and therefore be easy to.Owing to these reasons, compression moulding and float glass process moulding are suitable, and for above-mentioned moulding, compression moulding is particularly suitable.

Being suitable for the glass of above-mentioned substrate 1-5 or glass ceramics or its substrate glass (will by thermal treatment to form the glass of glass ceramics) will describe about its composition below.

By water or infrared absorbent are added in the following basic composition, each substrate has the suitable composition that improves infrared absorption.The common ground of this basic composition is that this basic composition contains SiO ₂And Ai ₂O ₃Initially contain SiO ₂And Ai ₂O ₃Composition near 3 mum wavelengths, have clearly absorption peak and therefore be preferably basic composition.In the method that adds infrared absorbent, preferably the oxide with any additives adds in the batching.As for adding water, use oxyhydroxide as raw material, gas bubbling or adopt oxyhydroxide to combine with above-mentioned boiling in melten glass of containing steam as raw material.The preferred oxyhydroxide that uses is as raw material.Particularly, for containing SiO ₂And Ai ₂O ₃Composition, preferably use aluminium hydroxide so that obtain desirable water cut.

In addition, also preferably contain SiO ₂And B ₂O ₃Glass or glass ceramics.In this case, preferably use H ₃BO ₃Raw material as glass or glass ceramics.

Preferred basic composition comprises following composition.

(composition 1)

Composition 1 contains 62-75%SiO in weight % ₂, 5-15%Ai ₂O ₃, 4-10%Li ₂O, 4-12%Na ₂O and 5.5-15%ZrO ₂, and Na ₂O/ZrO ₃Weight ratio is 0.5-2.0 and Ai ₂O ₃/ ZrO ₂Weight ratio is 0.4-2.5.The glass that preferably will have above-mentioned composition is applied to substrate with the amorphous glass form.

Composition 1 can strengthen by chemistry realizes dark compressive stress layers, high flexural strength and high Nu Pushi hardness, big and Vickers hardness is big because of its Nu Pushi hardness, it strengthens substrate as chemistry and has fabulous performance, preferably carries out above-mentioned chemistry by ion-exchange in the processing that contains Na ion and/or K ion is bathed and strengthens.Bathe as the processing that contains Na ion and/or K ion, preferred use contains the processing bath of sodium nitrate and/or potassium nitrate.But ion gun should be not limited to nitrate, and can be selected from sulfate, hydrosulfate, carbonate, supercarbonate or halogenide.When the processing bath contained the Na ion, the Li ion in Na ion and the glass carried out ion-exchange.When the processing bath contained the K ion, the Na ion in K ion and the glass carried out ion-exchange.When the processing bath contained Na ion and K ion, Li ion in Na ion and K ion and the glass and Na ion carried out ion-exchange respectively.In above-mentioned ion-exchange, therefore the alkali metal ion in the surface layer of glass part is formed compressive stress layers by the big alkali metal ion displacement of a kind of ionic radius in the surface layer of glass part, cause this glass to be strengthened by chemistry.

Composition 1 is preferably, and in weight %, contains 63-71%SiO ₂, 7-14%Ai ₂O ₃, 4-7%Li ₂O, 6-11%Na ₂O, and 6-12%ZrO ₃, and Na ₂O/ZrO ₂Weight ratio is 0.7-1.8 and Ai ₂O ₃/ ZrO ₂Weight ratio is 0.6-2.0.

Composition 1 can contain normally used clarificant, for example Sb ₂O ₃

In above-mentioned basic composition, hydroxyl is attached to the water in the glass, and strong effect remains in the glass water.Therefore can access suitable infrared ray absorbing performance by the water that adds scheduled volume.In addition, also can be easy to obtain suitable infrared ray absorbing performance by adding infrared absorbent.

Can the above-mentioned glass of following manufacturing.The glass material that the composition of wanting for obtaining is prepared is about 1,500-1, and 600 ℃ of heating following fusion in about 5-8 hour is so that be desirable shape with glass ware forming.Said composition 1 is suitable for compression moulding.

(composition 2)

Composition 2 contains 40-65%SiO in mol% ₂, 1-10%Ai ₂O ₃, 5-25%Li ₂O, 0-15%Na ₂O, 0-30%CaO,, 0-20%MgO (CaO and MgO total content are 2-30%), 0-10%TiO ₂And 0-10%ZrO ₂(Ti ₂O and ZrO ₂Total content is 2-20%), the total content of said components is at least 95%.The glass applications that preferably will have above-mentioned composition is in the substrate of amorphous glass form.In addition, a kind of glass with above-mentioned composition can improve substrate intensity effectively by chemical enhancing, so said composition is as being had excellent properties by substrate and the chemical substrate that strengthens that chemistry strengthens.

Composition 2 has the first preferred compositing range, and the composition 2 of first compositing range contains, and in mol%, contains 40-65%SiO ₂, 1-10%Ai ₂O ₃, 5-25%Li ₂O, 0-15%Na ₂O, 1-30%CaO, 0-10%MgO (CaO and MgO total content are 2-30%), 0.1-10%TiO ₂And 1-10%ZrO ₂(TiO ₂And ZrO ₂Total content is 2-15%), the total content of said components is at least 95%.More preferably ZrO ₂Content greater than TiO ₂Content.

Composition 2 has the second preferred compositing range, and the composition 2 of second compositing range contains, and in mol%, contains 40-65%SiO ₂, 2-8%Ai ₂O ₃, 8-20%Li ₂O, 1-10%Na ₂O, 5-25%CaO, 0-8%MgO (CaO and MgO total content are 5-25%), 0.1-8%TiO ₂, and 3-8%ZrO ₂(TiO ₂And ZrO ₂Total content is 3.1-12%), the total content of said components is at least 95%.Preferred ZrO ₂Content greater than TiO ₂Content.

In addition, in above-mentioned preferred compositing range, preferred Li ₂O and Na ₂The total content of O is 10-25%, and preferred SiO ₂Content greater than 50% but less than 65%, in addition, preferred Ai ₂O ₃Content be at least 2% but less than 6%, and the content of preferred CaO greater than 9% but be not more than 25%.Also preferred Li ₂The content of O is at least 10% and preferred TiO ₂Content is at least 0.2% still less than 5%.

In above-mentioned composition, preferred especially SiO ₂, Ai ₂O ₃, Li ₂O, Na ₂O, ZrO ₂, TiO ₂, the total content of CaO and MgO is 100%, perhaps sneaks into based on this composition to be the Sb less than 1% weight ₂O ₃

According to above-mentioned basic composition, hydroxyl is attached to the water in the glass and produces strong effect water is remained in the glass, therefore can obtain suitable infrared ray absorbing performance by the water that adds scheduled volume, in addition, also can easily obtain suitable infrared ray absorbing performance by adding infrared absorbent.

Composition 2 has fabulous water tolerance.Water tolerance can be expressed as Rab/Raf, wherein Raf is to be when preserving 24 hours in 80 ℃ the water with glass in temperature, have the center line average roughness of glass substrate surface of the basic composition of composition 2, Raf is the center line average roughness that recorded before above-mentioned preservation.Rab/Raf value with glass substrate of composition 2 is generally 0.8-1.When the Rab/Raf value more near 1 the time, this glass substrate has better water tolerance and the surfaceness degree of deterioration is littler.The Rab/Raf value is preferably 0.84-1.In addition, the center line average roughness Rab before being kept at glass in the water is preferably 0.1-0.5, and above-mentioned Rab and Raf can utilize atomic force microscope (AFM) to measure.

The Young modulus of preferred this glass substrate is 90-120GPa, more preferably 95-120GPa.

Therefore the glass substrate that has composition 2 can be applied to a kind of information recording carrier of excellent stability during high speed rotating, and can provide surface smoothness very high information recording medium substrate.

For the hot expansibility with the fixture of the hot expansibility of substrate and fix information recording medium is complementary, the average thermal linear expansion coefficient of preferred glass substrate is measured as 80 * 10 at 100-300 ℃ ^-7/ ℃ or bigger.

In addition, when this glass substrate satisfied above-mentioned water tolerance, Young modulus and expansion coefficient, the proportion of this glass substrate was preferably 3.1 or littler, and more preferably 2.9 or littler.For example can limit this glass composition, so that obtain the proportion of 2.3-2.9.In addition, for reducing the thermal capacitance of substrate, it also is preferred reducing proportion.

Strengthen glass substrate with the method chemistry identical with composition 2 with the chemical enhancement methods of glass substrate with composition 1.

In view of the step of chemistry enhancing step and/or formation information recording layer, the glass transformation temperature of preferred glass substrate material is 500 ℃ or higher.When glass transformation temperature is too low, can cause a problem, be about to be used for the sodium nitrate of chemical humidification or potassium nitrate can not be under the said temperature condition fusion or in order to form information recording layer on the glass substrate or like that and heating that adopt makes the substrate distortion.In the time of aspect considering these, can determine this glass composition, making glass transformation temperature is 500-600 ℃.

This glass substrate shows at the glass substrate that will be strengthened by chemistry and between the glass substrate that chemistry has strengthened, Young modulus, above-mentioned expansion coefficient, glass transformation temperature and proportion are almost constant, and the Rab/Raf value remains unchanged or increases (being limited to 1 on it).Above-mentioned composition has fabulous water tolerance, and even when being cleaned, its substrate does not have surface roughening yet.

Composition 2 is suitable for compression moulding.

(composition 3)

Composition 3 contains 35-70%SiO in mol% ₂, 1-15%Ai ₂O ₃, 1-45%CaO, MgO and CaO total amount are 3-45%, Li ₂O and Na ₂The O total amount is 3-30%, 0.1-10%TiO ₂Above-mentioned composition is suitable as the basic composition of amorphous glass substrate, and has high Young's modulus and fabulous compression moulding.In addition, it also is applicable to the chemically strengthening glass substrate.

According to above-mentioned basic composition, hydroxyl is attached to the water in the glass and produces strong effect water is remained in the glass, therefore can obtain suitable infrared ray absorbing performance by the water that adds scheduled volume, in addition, also can easily obtain suitable infrared ray absorbing performance by adding infrared absorbent.

(composition 4)

Composition 4 contains 45-70%SiO in mol% ₂, 1-15%Ai ₂O ₃(SiO ₂And Ai ₂O ₃Total content be 57-85%), 2-25%CaO, 0-15%BaO, 0-15%MgO, 0-15%SrO, 0-10%ZnO (SrO, the total content of BaO and ZnO are 2-30% for MgO, CaO), 2-15%K ₂O, 0-8%Li ₂O, 0-8%Na ₂O (K ₂O, Li ₂O and Na ₂The O total content is 2-15%), 0-12%ZrO ₂And 0-10%TiO ₂, the total content of said components is at least 95%, and the glass that preferably will have above-mentioned composition is applied to substrate as a kind of amorphous glass.In above-mentioned compositing range, can stably obtain glass transformation temperature than higher glass, so this glass is suitable as a kind of even high-temperature heat treatment substrate of not thermal deformation.Therefore above-mentioned composition is the basic composition that is applicable to the perpendicular magnetic recording medium substrate.

In addition, preferred composition 4 contains 50-67%SiO in mol% ₂, 2-12%Ai ₂O ₃(SiO ₂And Ai ₂O ₃Total content be 57-79%), 3-20%CaO, 0-14%BaO, 0-10%MgO, 0-10%SrO, 0-8%ZnO (SrO, the total content of BaO and ZnO are 3-30% for MgO, CaO), 0-5%Li ₂O, 0-5%Na ₂O, 4-12%K ₂O, (K ₂O, Li ₂O and Na ₂The O total content is 4-12%), 0-10%ZrO ₂And 0-8%TiO ₂

In above-mentioned compositing range, preferred especially SiO ₂, Ai ₂O ₃, MgO, CaO, BaO, K ₂O and ZrO ₂Total content be at least 98%, more preferably be at least 99%, also more preferably 100%.When above-mentioned composition contains Sb in a small amount ₂O ₃The time, fluoride, chloride, SO ₃And As ₂O ₃During as required as defoamer, its content based on said composition is preferably 2% weight or littler, as approximate restriction, and 1% weight or littler more preferably, from the viewpoint of environmental protection, do not use for example As of any arsenide ₂O ₃Be desirable.

Do not contain TiO ₂Above-mentioned composition be fabulous in the effect that reduces aspect the substrate surface roughness.

The excellent part of above-mentioned composition is that glass transformation temperature is at least 620 ℃ usually, preferably is at least 650 ℃, more preferably is at least 680 ℃, also more preferably be at least 700 ℃, or it has high-fire resistance.Though the upper limit of above-mentioned glass transformation temperature is not particularly limited, it is typically about 900 ℃.Because above-mentioned composition has this high-fire resistance, so when carrying out high-temperature heat treatment in the manufacturing process at perpendicular magnetic recording medium, can prevent the substrate distortion.

According to above-mentioned basic composition, hydroxyl is attached to the water in the glass and produces strong effect water is remained in the glass, therefore can obtain suitable infrared ray absorbing performance by the water that adds scheduled volume, in addition, also can easily obtain suitable infrared ray absorbing performance by adding infrared absorbent.

In addition, above-mentioned composition can strengthen by chemistry, in this case, preferably carries out ion-exchange by substrate is immersed in the fused salt that contains the K ion.

In addition, above-mentioned composition is to acid excellent performance aspect the permanance of hydrofluosilicic acid and the water tolerance for example, even and substrate by with acid treatment or cleaning, substrate surface does not have roughening yet.

Composition 4 is suitable for compression moulding and float glass process moulding, and is particularly suitable for compression moulding.But, when adopting the float glass process moulding, must avoid adding Sb ₂O ₃And As ₂O ₃Any.

(composition 5)

Composition 5 contains 55-70%SiO in mol% ₂, 1-12.5%Ai ₂O ₃, 5-20%Li ₂O, 0-12%Na ₂O, 0-2%K ₂O, 0-8%MgO, 0-10%CaO, 0-6%SrO, 0-2%BaO, 0-8%TiO ₂, and 0-4%Zr.The glass that preferably will have above-mentioned composition is applied to substrate as a kind of amorphous glass.Strengthen the intensity can improve the substrate that above-mentioned composition makes effectively by chemistry, thus said composition as the substrate that will be strengthened by chemistry and chemistry enhancing substrate have excellent properties.

According to above-mentioned basic composition, hydroxyl is attached to the water in the glass and produces strong effect water is remained in the glass, therefore can obtain suitable infrared ray absorbing performance by the water that adds scheduled volume, in addition, also can easily obtain suitable infrared ray absorbing performance by adding infrared absorbent.

Composition 5 is suitable for compression moulding and float glass process moulding, and is particularly suitable for compression moulding.But, when adopting the float glass process moulding, must avoid adding Sb ₂O ₃And As ₂O ₃In any.

(composition 6)

Composition 6 contains 58-66%SiO ₂, 13-19%Ai ₂O ₃, 3-4.5%Li ₂O, 6-13%Na ₂O, 0-5%K ₂O, 10-18%R ₂O (R ₂O=Li ₂O+Na ₂O+K ₂O), 0-3.5%MgO, 1-7%CaO, 0-2%SrO, 0-2%BaO, 2-10%R ' O (R ' O=MgO+CaO+SrO+BaO) and 0-2%TiO ₂The glass that preferably will have above-mentioned composition is applied to substrate as a kind of amorphous glass.Strengthen the intensity can improve the substrate that above-mentioned composition makes effectively by chemistry, thus said composition as being had excellent properties by the substrate that chemistry strengthens, therefore above-mentioned glass can be strengthened by chemistry.

According to above-mentioned basic composition, hydroxyl is attached to the water in the glass and produces strong effect water is remained in the glass, therefore can obtain suitable infrared ray absorbing performance by the water that adds scheduled volume, in addition, also can easily obtain suitable infrared ray absorbing performance by adding infrared absorbent.

Composition 6 is suitable for compression moulding and float glass process moulding.But, when adopting the float glass process moulding, must avoid adding Sb ₂O ₃And As ₂O ₃In any.

(composition 7).

Composition 7 contains 40-80%SiO ₂, 1-10%Ai ₂O ₃, 0-20%B ₂O ₃, 0-20%R ₂O (R ₂O=Li ₂O+Na ₂O+K ₂O) and 0-10%R ' O (R ' O=MgO+CaO+SrO+BaO).The glass that preferably will have above-mentioned composition is applied to substrate as amorphous glass.Said composition strengthens the intensity to improve the substrate that above-mentioned composition makes effectively by chemistry, so have excellent properties as the substrate that will be strengthened by chemistry and the substrate of chemistry enhancing.

(composition 8)

Composition 8 be by substrate glass under thermal treatment crystallization and glass (glass ceramics), and this glass ceramics is used as substrate.Above-mentioned glass ceramics is a kind of like this product, and the crystallization phase that wherein contains enstatite and/or enstatite solid solution precipitates by substrate glass thermal treatment.Enstatite is the crystalline solid that is made of Si, Mg and O, and this substrate glass contains SiO ₂, MgO and Ai ₂O ₃As key component.

Preferred composition 8 does not contain Li ₂O and ZnO, in addition, as crystallization phase, preferred composition 8 does not contain the crystallization phase of spinel structure and two lithium metasilicate crystal.

Enstatite and solid solution thereof have a kind of like this structure, and wherein the Si of strong bond combination is connected the form of chaining with O, and thisly connect in conjunction with extending with plane form by Mg.Therefore crystal grain is incorporated into amorphous phase by strong bond.On the contrary, two lithium metasilicate crystal have sphere or its its major diameter and minor diameter the to a certain degree form of difference are arranged, and its strength ratio that is attached to amorphous phase is less.The bond strength of crystal grain and amorphous phase is greatly or little, and is influential to the easy degree of crystal grain disassociation on the substrate surface.When substrate during, because the thermal expansion coefficient difference between crystallization phase and the unformed layer homologue, be present in crystal grain in the substrate surface and become and be easy to disassociation by Fast Heating.But according to above-mentioned glass ceramics, the disassociation of crystal grain has been prevented from, and can prevent to occur in the substrate surface concave defects.In having the glass ceramics of crystallization phase, this crystallization phase contains enstatite and/or its solid solution, and the thermal expansivity of this crystallization phase and the thermal expansivity of amorphous phase are approaching each other, and the power of therefore separating crystal grain is not easy to work.On the contrary, in the glass ceramics that contains two lithium metasilicate crystallization phases, it is another 2 or 3 times that the thermal expansivity of the crystallization phase mode different with the thermal expansivity of amorphous phase is one, and the power of therefore separating crystal grain increases.

Be the substrate glass of forming composition 8, compression moulding is suitable, and the thermal treatment that is preferred for crystallization is carried out after compression moulding.

(composition 9)

Composition 9 be by substrate glass under thermal treatment crystallization and a kind of glass (glass ceramics) and be applied to substrate.This substrate glass has a kind of composition, and said composition contains 35-65%SiO in mol% ₂, greater than 5% but be not more than 20% Ai ₂O ₃, 10-40%MgO and 5-15%TiO ₂, the total content of said components is at least 92%.

Preferred composition 9 does not contain Li ₂O and ZnO, in addition, as crystallization phase, preferred composition 9 does not contain the crystallization phase of spinel structure and two lithium metasilicate crystal.

When thermal treatment, above-mentioned substrate glass produces a kind of glass ceramics, and this glass ceramics contains the crystallization phase that is made of enstatite and/or enstatite solid solution, therefore, similar with composition 7, above-mentioned glass ceramics can be used in and stops the crystal grain disassociation and prevent that concave defects from appearing in the substrate surface.

Be the substrate glass of forming composition 9, compression moulding is suitable, and the thermal treatment that is preferred for crystallization is carried out after compression moulding.

In composition 8 or composition 9, preferred crystallite dimension is 100nm or littler, 50nm or littler more preferably, also more preferably crystallite dimension in the 1-50nm scope.

＜information recording carrier and manufacture method thereof 〉

Information recording carrier of the present invention will be in following explanation, information recording carrier of the present invention comprises multilayer film, these multilayer film contain the information recording layer that forms on above-mentioned information recording medium substrate, according to recording mode, this information recording carrier mainly is categorized as magnetic recording media, Magnetooptic recording medium, CD or the like.This information recording carrier is specially adapted to magnetic recording media, and this information recording carrier will describe in detail as examples of implementation with magnetic recording media.

In the multilayer film that contain the information recording layer (magnetic recording layer) that forms on above-mentioned substrate first type surface, the layer that forms multilayer film comprises that for example undercoat, protective seam, lubricating layer or the like also have magnetic recording layer in addition.Composition of these layers and layer structure depend on the technical requirement of expectation.Magnetic recording layer is formed by magnetosphere or is formed by magnetosphere and non-magnetosphere, preferably contains the principal ingredient of Co alloy as magnetosphere.Yet the selection of undercoat is decided on magnetosphere, and when magnetosphere was formed by the Co alloy, the preferred use contained Cr alloy (for example contain the CrW alloy, contain the CrMo alloy or contain the CrV alloy).Protective seam comprises carbon protective film.Lubricating layer comprises by using dilution PFPE such as containing the freon solvent and using the layer that this dilute solution forms.Preferred above-mentioned undercoat, magnetosphere, nonmagnetic layer and protective seam form by sputter, and above-mentioned layer structure is applicable to the longitudinal magnetic recording medium.

For the longitudinal magnetic recording medium, preferred heated substrate before forming each layer step.

In perpendicular magnetic recording medium, for example inculating crystal layer, soft magnetosphere, nonmagnetic layer, magnetosphere (magnetic recording layer), protective seam and lubricating layer are formed on the substrate.With infrared radiation heating preferably after soft magnetosphere forms but before nonmagnetic layer forms, carry out, perhaps after magnetosphere forms but before protective seam formation, carry out.

Above-mentioned heating has improved magnetic recording property, and can proofread and correct the anisotropy of magnetic susceptibility of soft magnetosphere.Can apply magnetic field at substrate between the period of heating.

Inculating crystal layer comprises Ti alloy-layer and Cr alloy-layer.Soft magnetosphere comprises FeTaC layer, FeCoB layer, CoTaZr layer, CoNbZr layer, NiFe layer and FeAlSi layer.Nonmagnetic layer comprises Ti alloy-layer and NiTaZr layer.

Magnetosphere comprises the Co alloy-layer, and protective seam comprises carbon-coating.Lubricating layer comprises same as mentioned above layer.

In recent years, the sandwich construction that contains magnetic recording layer has the trend that increases number of plies amount, so that improve magnetic characteristic and electromagnetic conversion properties, and some magnetic recording media has 8 layers or more layers that forms by sputter, fixing and relative sputtering method uses the sputter equipment of multi-cavity series connection, and can make these chambeies all become vacuum state.Sputter gas for example argon gas can be introduced into each chamber as required, substrate is introduced into this device and is heated in the first section forming cavity, then substrate is transmitted to last section along this chamber, in these chambeies, pile up continuously to form multi-layer film structure by the layer that sputter forms.One of second section forming cavity chamber can be provided with heating arrangement and be used for the substrate that heating-up temperature has descended.For boosting productivity and avoiding the further increase of equipment size, it is desirable to, substrate heats in the first section forming cavity, and when substrate temperature is suitable for forming each layer, finishes the formation of each layer by sputter.Yet,, be difficult to make substrate temperature until finish all to remain in the proper range along with the number of plies amount that will pile up increases.Have only when substrate has enough temperature, could form the enough information recording carrier layers of coercive force, heated substrate and when forming information recording layer and then after need not heating the layer that can form and forming can form said sequence that chamber, heating chamber and film form the chamber along film and transmit substrate and produce information recording carrier.

In the tandem sputtering method, substrate is begun transmission and forms the district along film to transmit from the heating zone, pile up each layer continuously to form multilayer film (need not heat the layer that can form can form) before substrate is sent to the heating zone by sputter, therefore caused the fixing problem that has equally with relative sputtering method.

According to information recording medium manufacturing method provided by the invention, can overcome the problems referred to above, information recording medium manufacturing method provided by the invention comprises four embodiments, i.e. method 1-4.

Method 1 is a kind of by form the method that the multilayer film contain information recording layer come the manufacturing information recording medium on information recording medium substrate, this method comprises that the described substrate that heats in the heating zone forms the district along continuous film and transmits, the average firing rate of this substrate is at least 10 ℃/second, preferably be at least 15 ℃/second, more preferably be at least 20 ℃/second, also more preferably be at least 30 ℃, form the district at film and be formed for constituting the floor of described multilayer film continuously to form multilayer film.Above-mentioned multilayer film can be the films that is made of information recording layer or can be the films that information recording layer and other layer constitute.Because the time that heating needs can shorten, the output of this information recording carrier can improve.In said method, the bulk information recording medium can be produced by batch in a production line, and by increasing heating of substrate speed, the bulk information recording medium can spend the short cycle manufacturing.As a result, production cost significantly descends, and the performance high product can be provided under lower cost.

Preferred said method 1 is a kind of like this method, wherein is equal to each other with the residence time that forms in the district at each film in the residence time of heating zone.Preferably substrate is transmitted in addition and enter the heating zone and transmit substrate and leave each film and form the district and carry out synchronously.Among the above-mentioned preparation method, residence time of (heating chamber) and substrate increased or reduce in the mode that is associated in the residence time that each film forms district's (each sputtering chamber) substrate in the heating zone.Form the total residence time in district at film, promptly each film residence time of forming the district multiply by the time representation that the number of plies amount that will form by sputter gets and forms the required accumulated time of each floor by sputter.When above-mentioned accumulated time increased, substrate temperature descended, and substrate temperature more likely drops to than being applicable to that sputter forms the lower temperature of temperature of each layer as a result.In order under the situation that does not reduce the number of plies amount that will form, to shorten above-mentioned accumulated time, need to reduce the residence time that forms the district at each film by sputter.For this purpose, also shorten residence time in the heating zone.In above-mentioned manufacture method, the average firing rate of substrate in the heating zone is 10 ℃/second or bigger, continues one period short time so this substrate can be heated to temperature desired, and can form each layer by sputter in suitable substrate temperature scope.In the magnetic recording media with more multi-layered multilayer film is made, perhaps in the magnetic recording media that is requiring to form each layer under higher temperature is made, except the heating zone in first chamber, the heating zone can be arranged on first and the chamber, end between the chamber.With the infrared radiation heating is a kind of method that is applicable to heated substrate, when carrying out infrared radiation during the step that is forming each layer, and these layers reflected infrared, the infra-red intensity that the result will be absorbed in the substrate reduces.Therefore preferably before forming each layer beginning, heat, and more preferably before forming each layer beginning, carry out above-mentioned heating immediately with infrared radiation.Preferred especially this heating means are used to make the longitudinal magnetic recording medium.In addition, can adopt a kind of structure, need not heat the layer that can form in this structure is formed on the substrate, heat this substrate in the heating zone, form the multilayer film that contain the information recording carrier layer then, in this case, when heating with infrared radiation, the layer segment reflected infrared that forms before the heating.But, during among using substrate 1-5 any, can produce sufficient thermal effect.Said method is suitable for making perpendicular magnetic recording medium.

As mentioned above, heating of substrate speed is improved, the time that forms each layer thus also shortens, and the result can form each layer when substrate reaches sufficiently high temperature.In addition, because total production time can significantly shorten, so improved output and can reduce production costs.Therefore can stably provide premium quality product for market.When the number of plies amount that constitutes multilayer film increased, it is remarkable that above-mentioned trend becomes.In method 1, preferably utilize the infrared radiation heated substrate.

Method 2 is a kind of like this methods, and it comprises and utilize infrared radiation above-mentioned information recording medium substrate provided by the invention (any among the substrate 1-5) to heat this substrate, and form the multilayer film that contain information recording layer on substrate.

In method 2, use the high substrate of a kind of infrared ray absorbing efficient, and utilize infrared radiation to heat this substrate, therefore can access high firing rate comes heated substrate.Utilize infrared radiation heating for above-mentioned, the radiation spectrum maximum wavelength is 2,750nm-3, and the infrared source in the wavelength coverage of 700nm is suitable.Well heater is suitable as above-mentioned infrared source.When above-mentioned well heater can be considered to black matrix, preferably heter temperature is adjusted to 600K-1,000K, 700K-900K more preferably is complementary near being used to make the absorption peak of the maximum wavelength of radiation spectrum and substrate.

Suitable well heater is a kind of carbon heater, and when well heater was disposed in the heating chamber, the partial pressure of oxygen in the heating atmosphere reduced, and wears out through peroxidation so can reduce carbon heater.

Preferably before forming each layer beginning, utilize infrared radiation to heat (before the layer of needs heating forms), and more preferably before forming each layer beginning, carry out above-mentioned heating immediately, because about method 1 described same cause, said method can make up.

Method 3 is methods of a kind of manufacturing information recording medium, and it is included on the information recording medium substrate provided by the invention and forms information recording layer, utilizes infrared radiation to heat this substrate then.Be formed with the substrate of information recording layer on it with infrared radiation, this infrared ray is by the information recording layer partial reflection, and the infra-red intensity that arrives substrate reduces.But owing to use above-mentioned substrate, the infrared ray that arrives substrate is absorbed in the substrate, therefore can fully obtain the effect of heated substrate.

Method 4 is methods of a kind of manufacturing information recording medium, it is included in, and (any among the substrate 1-5) forms information recording layer on a kind of information recording medium substrate, this substrate is made by glass that contains infrared absorbent or glass ceramics, this absorbing agent is the oxide of the metal of at least a chosen from Fe, copper, cobalt, ytterbium, manganese, neodymium, praseodymium, niobium, cerium, vanadium, chromium, nickel, molybdenum, holmium or erbium, and utilizes the infrared radiation heated substrate.

Method 3 and 4 is applicable to the manufacturing perpendicular magnetic recording medium, utilizes infrared radiation to heat by above-mentioned, can improve magnetic recording characteristic, and can proofread and correct the anisotropy of magnetic susceptibility of soft magnetosphere.After the heating, can form for example protective seam or the like by sputter.

Preferably providing a plurality of films to form the district in method 3 and method 4 forms each floor that constitutes the multilayer film that contain information recording layer and provides a heating zone to come heated substrate, and substrate is transmitted by continuous district to form multilayer film, in this case, the heating zone is arranged on the film that is used to form information recording layer and forms position afterwards, district.In these methods, preferably will be adjusted to and be equal to each other in residence time of heating zone with in the residence time that each film forms the district.In these methods, because the efficiency of heating surface has improved, the heating of therefore carrying out the short time just can produce sufficient thermal effect, cause to shorten heat time heating time, and can significantly reduce the needed time of Overall Steps.Output improves as a result, and a large amount of high-quality information recording carriers can be provided under low cost.In method 3 and method 4, also preferably use the identical heating source described in method 2.

In arbitrary method among method 1-4, consider that Fast Heating causes that substrate destroys, it is desirable to average firing rate is 200 ℃/second or littler.In addition, in each method, be preferably 2-10 second in the residence time in each heating zone and film formation district.

For minimizing adheres to the foreign impurity on the substrate surface and prevents formation than the coarse grain magnetosphere, it is desirable shortening heat time heating time and film formation time.

In arbitrary method among method 1-4, preferably use a kind of fixing and relative sputter equipment, and more preferably use the fixing and relative sputter equipment of monocrepid feed.

In the where method in office, preferably in 2 seconds or shorter time, substrate is sent to another chamber from a chamber.

When the summation of cambial time cycle is 24-300 during second, information recording medium manufacturing method provided by the invention is suitable for.

According to arbitrary above-mentioned manufacture method, the information recording carrier layer can have sufficient coercive force, and for example coercive force is 3,600 oersteds or bigger, and preferred coercive force is 4,500 oersteds or bigger.

Embodiment

Further describe the present invention below with reference to embodiment, yet the present invention should in no way limit at these

In the embodiment.

Measuring the glass transformation temperature of glass and the kind of crystalline of spectral-transmission favtor and evaluation glass ceramics carries out according to following method.

(1) glass transformation temperature

In temperature rising speed is under+4 ℃/minute, measures 5 Φ * 20mm sample, SiO with the thermomechanical analyzer (TMA8140) that Rigakusha provides ₂As standard sample.

(2) spectral-transmission favtor

Be machined to the sample of smooth-shaped (at 2200nm-6 with spectrophotometer measurement, the FTIR-8400 measurement transmissivity that provides with Shimadzu Corporaion in the 000nm wavelength coverage and at 200-2, the V-570 that provides with Nippon Bunko in 500 wavelength coverages measures transmissivity), this spectral-transmission favtor comprises the loss that is caused by surface reflection.

(3) kind of crystalline of glass ceramics is identified

Utilize the X-ray diffraction (device: X-ray diffraction device MXP18 is provided tube voltage by Mac Science: 50kV, tube current: 300mA, scan angle 1-90 °) of the K alpha ray measurement powdery glass ceramics of Cu.Identify the crystal of precipitation according to the X-ray diffraction peak that obtains.

In addition, carrying out chemistry by method as described below strengthens.

Embodiment 1-12

The formulate glass raw material is SiO for example ₂, Al ₂O ₃, Al (OH) ₃Or the like, so that obtain a kind of composition, said composition has the content shown in table 1 and 2 (in mol%), and it is fully mixed, then the material of preparation is placed the heat fusing container and melt under the air temperature is 1,000 ℃ or higher temperature, the complete froth breaking of gained molten glass also is stirred so that glass becomes no bubble state.This glass is cast in the mould and is cooled to the approximately temperature about its glass transformation temperature gradually then.At once glass placed the annealing furnace maintenance 1 hour and make it at the stove cool to room temperature thereafter.The glass that obtains thus has fabulous homogeneity, and does not observe bubble and melted material not.

Glass among the embodiment 1-9 is machined to the plain film that every thickness is 2mm, and two surface is all by optical polish.

With the glass among the embodiment 10-12 in about 800 ℃ of left and right sides thermal treatments so that in every kind of glass precipitation seed, then glass temperature is elevated to about 1,000 ℃ so that carry out crystallization, precipitate the crystallization phase that contains enstatite, obtain glass ceramics thus.By transmission electron microscope observation the time, the glass ceramics crystallite dimension among the embodiment 10-12 is 50nm or littler, and these glass ceramicses also are machined to the plain film that every thickness is 2mm, and two surface is all by optical polish.

Measure the spectral-transmission favtor that each is machined to the sample of plain film shape, determining that wavelength is 2,750-3, the maximal value of transmissivity and minimum value and be 1 during 700nm at wavelength, spectral-transmission favtor during 000nm, table 1 and 2 shows these values and glass transformation temperature.At embodiment 1,2, in 4,5,7,8,10 and 11, the iron oxide amount of sneaking into (is Fe ₂O ₃) shown in table 1 and 2, calculate the liquid water content that obtains in every kind of glass by the OH amount of filling (charged) material.

Table 1

Embodiment		1	2	3	4	5	6
								Basic composition (mol%)	SiO 2	65.5	65.5	65.5	57.0	57.0	57.0
Al 2O 3	8.6	8.6	8.6	5.0	5.0	5.0
							Li 2O		12.5	12.5	12.5	14.0	14.0	14.0
Na 2O	10.4	10.4	10.4	2.0	2.0	2.0
							K 2O		0.0	0.0	0.0	0.0	0.0	0.0
MgO	0.0	0.0	0.0	6.0	6.0	6.0
							CaO		0.0	0.0	0.0	10.0	10.0	10.0
BaO	0.0	0.0	0.0	0.0	0.0	0.0
							ZrO 2		3.0	3.0	3.0	5.0	5.0	5.0
TiO 2	0.0	0.0	0.0	1.0	1.0	1.0
							Y 2O 3		0.0	0.0	0.0	0.0	0.0	0.0
Water cut (ppm)		80	200	300	60	200									300
							Fe 2O 3(ppm)		5000	1000	0	5000	1000	0
(*) 2,750-3, the minimum spectral-transmission favtor (%) of 700nm wavelength		50	30	18	50	29									19
							(*) 2,750-3, the maximum spectral-transmission favtor (%) of 700nm wavelength		68	60	50	65	58	46
(*) 1, the spectral-transmission favtor of 000nm wavelength (%)		76	89	92	75	88									91
							Glass transformation temperature (℃)		500			556
Kind of crystalline		Do not have			Do not have
								Being with or without chemistry strengthens		Have			Have

(*) each spectral transmission kilsyth basalt shows the value that is all recorded by the thick sample of the 2mm of optical polish by two surfaces

Table 2

Embodiment		7	8	9	10	11	12
								Basic composition (mol%)	SiO 2	63.0	63.0	63.0	46	46	46
Al 2O 3	4.0	4.0	4.0	10.5	10.5	10.5
							Li 2O		0.0	0.0	0.0	0.0	0.0	0.0
Na 2O	4.0	4.0	4.0	0.0	0.0	0.0
							K 2O		5.0	5.0	5.0	0.5	0.5	0.5
MgO	0.0	0.0	0.0	30.5	30.5	30.5
							CaO		13.0	13.0	13.0	0.0	0.0	0.0
BaO	3.0	3.0	3.0	0.0	0.0	0.0
							ZrO 2		4.0	4.0	4.0	0.0	0.0	0.0
TiO 2	4.0	4.0	4.0	9.0	9.0	9.0
							Y 2O 3		0.0	0.0	0.0	0.5	0.5	0.5
Water cut (ppm)		50	200	300	70	200									300
							Fe 2O 3(ppm)		5000	1000	0	5000	1000	0
(*) 2,750-3, the minimum spectrum transmission (%) of 700nm wavelength		51	28	18	39	19									13
							(*) 2,750-3, the maximum spectral transmission degree (%) of 700nm wavelength		70	61	48	52	44	20
(*) 1, the spectral transmission degree (%) of 000nm wavelength		74	88	91	55	63									65
							Glass transformation temperature (℃)		756			730
Kind of crystalline		Do not have			Enstatite
								Being with or without chemistry strengthens		Have			No

(*) each spectral transmission kilsyth basalt shows the value that is all recorded by the thick sample of the 2mm of optical polish by two surfaces

In each sample, wavelength is 2,750-3, and the spectral-transmission favtor minimum value during 700nm is 51% or littler, its maximal value is 70% or littler, iron is being introduced embodiment 1,2,4,5,7 wherein, in 8,10 and 11, wavelength is 1, and the spectral-transmission favtor during 000nm is less than 90%.

Make above-mentioned every kind of molten glass flow out and cut off respectively to obtain having each molten glass gob of predetermined weight from feeder, and each molten glass gob is fed separately on the compression moulding bed die spare, this mold members remains on this molten glass and can not adhere in the temperature range on it.Each glass gob is positioned at the mold spare compacting on bed die spare opposite then, so that it is laminar that glass gob is shaped to dish type.In this case, every kind of glass is big in the infrared region absorption, so it is because the velocity ratio of radiation cooling is lower.In directly suppressing, every kind of molten glass is pressed moulding therebetween, and they are soft state simultaneously, because every kind of glass is not easy cooling, the molding condition is easy.

Glass annealing with compression moulding, then in the central punch of each glass, follow its surfaces externally and internally of machine work, polishing two surfaces of each glass and lappingout should the surface, to obtain each external diameter is that 65.mm, thickness are that 0.635mm and center-hole diameter are the disk with magnetic disk substrate shape of 20.0mm, in addition, except above-mentioned machining steps, the disk among the embodiment 10-12 is by further crystallization.

Glass disk among the embodiment 1-9 is immersed in the fused salt so that its chemistry is strengthened.In embodiment 1-6, disk is dipped into the fused salt (380 ℃) 4 hours that contains sodium nitrate and potassium nitrate, and in embodiment 7-9, disk is dipped into the fused salt (420 ℃) 4 hours that contains potassium nitrate.

Embodiment 13

Utilize the monocrepid charging to fix and relative sputter equipment, form on every of many magnetic disk substrates and contain magnetospheric multilayer film, its substrate is to be made by the various glass of embodiment 1-6 or the various glass ceramicses among the embodiment 10-12.Fixing and the relative sputter equipment of this monocrepid charging has multi-cavity connects, and have with substrate from the position the preceding the chamber be sent to the function that is positioned at another chamber thereafter.With substrate a slice connect a slice ground from a chamber synchronous driving to another adjacent chamber.When the transmission of finishing substrate, and then each substrate stops a constant time in each chamber.During the above-mentioned residence time, substrate is heated in the chamber of primary importance, ground floor forms in second place chamber, and the second layer forms in chamber, the 3rd position, and in addition, the upper strata forms in the chamber of position thereafter.

Carbon heater is provided in the chamber of primary importance and by electricity and drives as 800K or higher infrared source.The input of well heater is set at 1KW.Come heated substrate by making substrate be positioned at the position relative with well heater.Near the optical absorption of each above-mentioned substrate wavelength 3 μ m is big, so they have absorbed effectively from the infrared ray of infrared source radiation and by Fast Heating.In first chamber as the heating zone, each substrate is about 30 ℃/second or bigger heating down in average firing rate, and they at short notice temperature become 200 ℃ or higher, the residence time of substrate in this chamber is set at 6.4 seconds.

Then, heated substrate is moved to the chamber of the second place and is parked in the position relative with sputtering target, by sputter the undercoat that the Cr alloy constitutes is formed on the substrate then, and in addition, substrate moved to another chamber from a chamber in 1 second.

In the chamber that comprises the 3rd position with thereafter in the chamber of position, nonmagnetic layer and Co alloy system magnetosphere are alternately formed, and the carbon-coating that sputter forms hydrogenation is as protective seam, so that produce the disk with 8 layers or more multi-layered multilayer film.This disk is produced in this manner continuously.PFPE solution in the freon solvent etc. is applied to each magnetic disk surface that takes out from sputter equipment, and with applying solution drying so that lubricating layer be formed on each disk.Because until all layers are formed by sputter, substrate all is in the condition of high temperature fully, the disk that takes out from sputter equipment has fabulous magnetic characteristic and electromagnetic conversion properties.For example, to have be 3,600 oersteds or bigger enough coercive forces to this disk.

The productive temp time cycle of above-mentioned manufacture method is 7.4 seconds, and it is to be 6.4 seconds and delivery time to be 1 second total residence time in the chamber.In contrast, when the glass substrate that uses does not contain infrared absorbent and water cut and do not reach scheduled volume, need spend about 1.5 times time heated substrate to reach same temperature.Even in 1 second substrate is sent to another chamber from a chamber, the productive temp time also will be approximately 1.5 times time, and this causes in producing by batch the difference of turnout huge.In the glass of embodiment 1 and 3, to compare with the example of not sneaking into water and iron, the average firing rate of the glass of embodiment 1 is enhanced 12% or more, and the average firing rate of the glass among the embodiment 3 is enhanced 20% or more.In the substrate in other embodiments, too average firing rate is improved.

Multilayer film are formed on each magnetic disk substrate, fix and relative sputter equipment, make this substrate with the glass among the embodiment 7-9 by the monocrepid charging.Inculating crystal layer and soft magnetosphere are formed on each substrate in each chamber, in heating chamber, heat each substrate with carbon heater, in each chamber, form nonmagnetic layer and magnetosphere then continuously, make perpendicular magnetic recording formula layer structure, in this example, the residence time in a chamber also equates with residence time in another chamber, and with substrate from a chamber synchronous driving to another chamber.Therefore when substrate was made by the glass among the embodiment 7-9, this glass also had the high IR beta radiation efficiency of heating surface, even under the situation that is not increased in the residence time in the chamber, substrate has been heated to sufficiently high temperature.So the vertically recording magnetic disc that so makes has fabulous magnetic characteristic and electromagnetic conversion properties.In addition; can use a kind of structure, the substrate of being made by the glass among the embodiment 7-9 wherein is provided, inculating crystal layer, soft magnetosphere, nonmagnetic layer and magnetosphere form by sputter; in heating chamber, heat each substrate then and heat-treat, and form protective seam with carbon heater.

When the foregoing description uses the monocrepid charging to fix with relative sputter equipment, can utilize the tandem sputter equipment to finish the formation of each layer of excellent performance.

Effect of the present invention

According to the present invention, a kind of information recording medium substrate can be provided, this substrate has the high IR beta radiation efficiency of heating surface, and a kind of information recording carrier with above-mentioned substrate is provided.

In addition, above-mentioned substrate can be maintained at the state of temperature that is suitable for forming multilayer film, and perhaps having information recording layer substrate formed thereon can be heated effectively, and therefore a kind of method of manufacturing information recording medium can be provided.In addition, owing to turnout is significantly increased, so can under low cost, provide high-quality information recording carrier for market.

Claims (6)

1. information recording medium substrate, it is made by containing above 200ppm water or the glass or the glass ceramics that contain infrared absorbent, wherein said glass has by the convert zone of 50% or the littler spectral light transmissivity that obtain of the thickness of glass of 2mm and is present in 2,750nm-3 is in the 700nm wavelength coverage.

2. information recording medium substrate, it is made by containing above 200ppm water or the glass or the glass ceramics that contain infrared absorbent, described glass is whole 2,750nm-3, spectral light transmissivity in the 700nm wavelength coverage is 70% or littler, and this spectral light transmissivity is obtained by the thickness of glass conversion of 2mm.

3. information recording medium substrate as claimed in claim 1 or 2, it will be heated by infrared radiation.

4. a kind of information recording carrier that contains the multilayer film that are formed on the information recording medium substrate as claimed in claim 1 or 2, these multilayer film contain information recording layer.

5. information recording medium manufacturing method, it comprise utilize the infrared radiation heating described in claim 1 or 2 information recording medium substrate and as described in form the multilayer film that contain information recording layer on the substrate.

6. information recording medium manufacturing method, it is included in and forms information recording layer on the information recording medium substrate as claimed in claim 1 or 2 and utilize infrared radiation to heat this substrate.